Volume 9 No. 2 July 2018 • pages 175-177 MALAYSIAN JOURNAL OF VETERINARY RESEARCH

SHORT COMMUNICATION

PARASCARIS EQUORUM IN A THOROUGHBRED HORSE IN PERAK TURF CLUB

PREMAALATHA B.1* , KARTIYAYINI S.2, SELVI V.2 AND SOHAYATI A.R. 1 Veterinary Research Institute, 59 Jalan Sultan Azlan Shah , 31400 Ipoh, Perak 2 Faculty of Veterinary Medicine,UPM, 43400 Serdang, Selangor * Corresponding author: [email protected]

ABSTRACT. In the Malaysian environment incubation period of the parasite is about 10- horses are primarily used in sports activities 15 weeks. (Lindgren et al., 2007) such as racing, endurance, dressage and Parascaris equorum has a direct life show jumping as well as in recreational cycle in which the transmission occurs pursuits and police work. Recently, the Perak through faecal oral route. Eggs laid by the Turf Club witnessed the death of a four-year- female adult ascarids in the intestine are old thoroughbred mare which was given passed into the environment through the enrofloxacin injection as treatment and was faeces of infected horses. The infective third regularly dewormed and vaccinated against stage larvae develop within 10 days in the equine influenza, Japanese encephalitis environment under optimum conditions and tetanus. Post-mortem examination in which the temperature ranges from of intestinal contents revealed presence 25 °C to 35 °C. The L3 stage could survive of worms. The sample was then sent to in the environment for 5 to 10 years. Upon the Veterinary Research Institute (VRI), ingestion of L3, the larvae colonise in the Perak for morphological identification of gastrointestinal tract of the host primarily in the worm. The worm was identified as small intestine and migrate to the liver and Parascaris equorum. Thus, awareness on lungs. Within 1 month, the larvae develop gastrointestinal parasites should be raised into fourth stage larvae upon returning to especially by recommending improved the small intestine. The adult worms achieve management practices such as proper patency about 75 to 80 days after infection manure disposal and deworming procedures by progressively maturing in small intestine. to control parasite infestations as well as Most horses acquire immunity in early years good management and nutrition. of life as the rare nematode induces absolute acquired immunity. In horses over 2 years of METHOD AND RESULTS age, patent infections are rarely diagnosed (Reinemeyer, 2009). Parascaris equorum is a nematode parasite Clinical signs and pathogenicity with world-wide distribution under the of Parascaris equorum infection ranges group of Ascaridoidea. It occurs mainly in from moderate to highly pathogenic the small intestine of yearlings or foals. The (Boyle and Houston, 2006). In infected

175 MALAYSIAN JOURNAL OF VETERINARY RESEARCH Volume 9 No. 2 July 2018

Figure 1. Morphological identification of Parascaris equorum (Photos by Premaalatha B.)

Figure 2. Full image of Parascaris equorum (length 20.3 cm) horses, the clinical signs include coughing, single rows at the inner surface of lip. At nasal discharge, anorexia, lethargy, the posterior, the male worm possesses a decreased growth and rough hair coat relatively longer tail with a small button- (Lind and Christenson, 2009). According like termination and has a small caudal alae. to Reinemeyer (2009), Parascaris equorum Females have a slit in the tail region (Snyder, infection also could cause enteritis and colic 1985). resulting in death sequel to perforation or The laboratory identification of gastrointestinal impaction. Parascaris equorum from faecal samples The worm can be identified collected from horse stables is through morphologically from the small intestines. simple faecal floatation. The eggs are dark It is a very large, white nematode that can brown with a thick shell. Methods such as range from 15 cm to 28 cm in length for the McMaster technique provide quantitative males and 40 cm to 50 cm in females (Taylor measures of the infection. However, there is et al., 2005). Please see Figures 1 and 2. The no correlation proven with the number of anterior part of the adult worm has a simple eggs shed in faeces and the degree of worm mouth opening with three prominent lips burden. To determine the resistance level which comprises of one dorsal and two of the worms towards specific dewormers, subventral lips surrounding a stoma. In the fecal egg count reduction test (FECRT) lateral view, the lips appear to be in the can be used (Reinemeyer, 2009). In this shape of a spade. Denticles are present in case, although treatment was given and

176 Volume 9 No. 2 July 2018 MALAYSIAN JOURNAL OF VETERINARY RESEARCH the horse was well taken care in terms of that could be taken include improving the nutrition and hygiene of stables, the worm management of working horses, proper was found in the intestines, which could be education to owners about negative effect due to resistance of worm to the given drug of worms in horses and having effective or a reduced dose which did not kill off all deworming schedule (Khan et al., 2017). the worms. Awareness on the importance of resistance of common worms to drugs used regularly DISCUSSION for deworming needs to be heightened. Regular screening for worm eggs by sending Treatment for Parascaris equorum infection faecal samples for laboratory diagnosis was primarily drugs of the macrocyclic is crucial to prevent an increasing load of lactones group such as Ivermectin and parasites in the animal. moxidectin. From surveys, the initial clinical evidence of failure of ivermectin or REFERENCES moxidectin to reduce ascarid eggs upon administration indicates macrocyclic lactone 1. Al-Emarah G.Y., Al-Ali S.J. and Al-Azizz S.A. (2008). Prevalence of Parascaris equorum infections in Karmat resistance. Multiple factors were discussed Ali in Basrah. Basrah Journal of Veterinary Research, 7(1): such as over usage of antihelminthics in 34-38. 2. Asmatullah K., Muhammad R., Abdul S., Farah S.B., breeder farms, the wide range of difference Muhammad A.K., Safiullah K.A., Muhammad H., Hafsah in effective dosage and recommended S., Waseem A., Sania A., Nazia I. and Gulmakia S. (2017). dosage for hardy parasites like Parascaris Epidemiological Prevalence and Role of Risk Factors in the Major Gastrointestinal Parasites in the Working equorum, the higher prevalence of resistant Equines. Indo American Journal Of Pharmaceutical ascarids in stables leading to transmission Sciences, 4(10): 3923-3927. 3. Boyle A.G., Houston R. (2006). Parasitic pneumonitis among facilities, and the pharmokinetics of and treatment in horses. Clin. Tech. Equine Pract. 5: 225- the drug itself persisting for longer time in 232. plasma leading to lower dose exposure to 4. Lind E.O. and Christensson D. (2009). Anthelmintic efficacy on Parascaris equorum in foals on Swedish new infections (Reinemeyer, 2009). Other studs. Acta Veterinaria Scandinavica, 51(1): 45 (4 pp). factors such as gender, hygiene, quality of 5. Lindgren K., Ljungvall O., Nilsson O., Ljungstrom B. L. Lindahl C. and Hoglund J. (2008). Parascaris equorum feed and hot weather were found to be in foals and in their environment on a Swedish stud contributing to the ascarid infection (Al- farm, with notes on treatment failure of ivermectin. Emarah et al., 2008). Pyrantel embonate and Veterinary Parasitology 151: 337-343 6. Reinemeyer C.R. (2009). Diagnosis and control of fenbendazole are currently successful and anthelmintic-resistant Parascaris equorum. Parasites & effective against treatment for the ascarid Vectors, 2(Suppl 2): S2-S8. 7. Snyder E.D. (1985). Scanning electron microscopy of (Lind and Christenson, 2009). adult Parascaris equorum (Nematoda). In: Proceedings In order to reduce costs on treatment, of the Helminthiological Society of Washington, 52(2): efficient prevention and control measures 237-243 8. Taylor M.A., Coop R.L. and Wall R.L. (2005). Veterinary need to be taken to overcome Parascaris Parasitology. Wiley Blackwell, Chichester, West Sussex. equorum infection. Primary control measures

177